I went back and reread an earlier post of mine - I'm about to put some poly primer on my doors as the last filler (finally!!) after a LOT of work with Rage and Icing (remember - me, rank amateur status )

There is some contradictory, but for sure, not necessarily wrong information in that May post. One says put my BC directly over the G2, another says to 2K then BC, then another suggests that I re-epoxy everything then BC.

Doesn't the 2 part poly mix constitute a 2K, or is the amount of the catylyst (more or less 50:1) so small as to not be able to call it that.

It really doesn't make much difference which way that I go except for time (and the fact that I'm running low on SPI epoxy) but durability is the underlying need - and the poly surface seems as hard as the 2K when finished with 220 then 360, final, 400-600.

Polyester primer is considered 2K, but when people speak of 2K they are generally referring to urethane 2K. I have shot urethane single stage directly over Featherfill G2 and it looked great, but for a really nice job epoxy should be the substrate for your finish coat. Poly primer is hard, but it is thought by many, including me, to be more brittle than some of the other 2K materials. It's claim to fame is massive fill with little shrinkage, not chip resistance or durability.

Any time you use a polyester product, you must use a 2k primer surfacer or a primer sealer over the polyester. Ployesters are designed to smooth out minor imperfections. They are the stepping stone from body filler to your high build primer surfacer. If you go directly to base, you will experience light pinholing, mapping and bad shrinking of the color. Polyesters are going to resemble a sponge effect. They are fairly porrous and can also have a bleed through into your color, because the hardener used has a peroxide element that causes discoloration. Good luck....

I would say that your best course of action would be cover the poly with epoxy and call it a day. Epoxy is pretty much the best substrate for base coat. If you use a chemically hot reducer you want have any problems with lifting if you use the epoxy. It acts as a good chemical and water barrier. As for as chip resistance and durability epoxies are far better than anything else out.

Silverbullet1967 is correct. The spray poly is not a primer!!! It is a spray body filler. You don't paint over bare body putty. After the spray poly,(body filler) you sand and then prime with 2K surfacer.
Dave Tallant Hot Rods. KC MO

Evercoat recomends spraying paint directly over G2 but you'll have much better gloss retention and durability if you use a urethane sealer/surfacer or best bet an epoxy primer/sealer before shooting your paint. This all has to do with the polyester primer being porus and soaking up solvent.

If you shoot two coats of epoxy then do a finesse sand the next day with 600 and shoot your color you'll have excellent results, good adhesion, good solvent barrier, and excellent gloss retention.

There are a couple of guys in this thread are giving general info about the nature of polyester primer that is outdated in regards to Evercoat Featherfill G2. It's is definitely not the same old poly primer we were using back in the 70's and 80's, and saying it needs to be sealed with epoxy is in the same vein as saying urethane 2K needs to be sealed with epoxy. Both G2 and urethane 2K are primer surfacers and have a certain amount of porosity, but both are designed to be topcoated successfully if desired.

Ireland's child, I suggest you call Fibreglass-Evercoat at (513)489-7600 and ask the tech people some questions, since the tech sheet on their site is outdated. I'm guessing you may wish to apply some epoxy anyway, but I want to make sure that the record is clear on this particular product.

You've seen it before and here it is again.
400 wet sanded G2,Omni MBC base,Chromabase 7500.
Outside of some missed sand scratchs which was my bad. It's excellent.
Yes you can achieve a great job over G2.
Now, This was a low buck job and considering the "pains" you've gone thru,I would go the epoxy route as I know you want this baby as good as it can get.
BUT, I would not hesitate to shoot base over fully cured G2 anyday.
Definetely NOT the same "old" poly primer it was.

Mike, is that your car? Nice Chevelle! Didn't you run into problems shooting over G2 awhile back on a Jr. Dragster project? If I remember right you had some swelling and mapping around the edges of the G2 because it wasn't sealed? I've shot base over G2 but noticed mapping on cut throughs and edges because of the differing absorbtion rates, the job has held up just fine though. Crash, are you shooting base over G2 on a regular basis without any sealer with no problems? G2 is a favorite of mine but I wouldn't paint directly over it on any job that I'm trying to achieve optimum results-maybe it's just me.

Crash, are you shooting base over G2 on a regular basis without any sealer with no problems? G2 is a favorite of mine but I wouldn't paint directly over it on any job that I'm trying to achieve optimum results-maybe it's just me.

Bob, I've only shot paint directly over G2 three times, twice with single stage urethane and once with bc/cc, though in the last case the base was white so it really wasn't much of a test. All the jobs looked fine, though like you I am sold on the epoxy for maximum quality. I just don't like to see it written that it "can't" be done when clearly it can, and in fact the product was designed by Evercoat with this function in mind, though obviously they have not been able to sell that aspect very well!

You've seen it before and here it is again.
400 wet sanded G2,Omni MBC base,Chromabase 7500.
Outside of some missed sand scratchs which was my bad. It's excellent.
Yes you can achieve a great job over G2.
Now, This was a low buck job and considering the "pains" you've gone thru,I would go the epoxy route as I know you want this baby as good as it can get.
BUT, I would not hesitate to shoot base over fully cured G2 anyday.
Definetely NOT the same "old" poly primer it was.

Mike,
N-I-C-E Chebbie

Looks like my course has been set. As much as I really don't want to put another coat of epoxy primer on this batch of car pieces that I have scattered around my shop and house, I really need to do it considering the number of hours that I have in just getting it straight enough to paint - if for no other reason then peace of mind.

(There are those days when I just wish that I had paid someone the $10K+/- to do my painting then I wouldn't have known what was under the shiny stuff!! )

And since I procrastinated, I have to call Baker PBE and order some SPI epoxy.

90% of the jr job's problems were MY fault along with it being in Dec. and 25*.I was having trouble with everything on that job mainly due to flash times and rushing coats but "if" I had let the G2 likely go another day,I'd been OK, Main problem was the Black Nason base and not letting it go longer before recoating and it WAS mainly the cut thrus and some wrinkling just due to too much too soon,But, I went ahead and shot a sealer over it thinking the G2 was the problem and,well,That's one I'd "really" like to forget.LOL..... That was the one job where EVERYTHING went wrong,but I learned a lot as well.
Winter paint work just stinks period.
The Chevell's a 69 and is Dougs,The guy who gave me the Rancharo.

90% of the jr job's problems were MY fault along with it being in Dec. and 25*.I was having trouble with everything on that job mainly due to flash times and rushing coats but "if" I had let the G2 likely go another day,I'd been OK, But, I went ahead and shot a sealer over it and,well,That's one I'd "really" like to forget.LOL..... That was the one job where EVERYTHING went wrong,but I learned a lot as well.
Winter paint work just stinks period.
The Chevell's a 69 and is Dougs,The guy who gave me the Rancharo.

How can I ever get that lucky - and now all you need is that 351W w/E4OD and that new tailgate - doesn't Doug have them?

I have to tell you, I have done it too. I sprayed a bc/cc black job over an unsealed Slick Sand, it showed zero issues when I saw the car about 8 months later. On another project with a pearl bc/cc it was years and still showing no problem. These were both "tests" of the product, and they performed well.

But on a show quality car that I wanted to stay real nice, I think I would have to apply an epoxy or urethane over it.

Register Now

In order to be able to post messages on the Hot Rod Forum : Hotrodders Bulletin Board forums, you must first register.
Please enter your desired user name (usually not your first and last name), your email address and other required details in the form below.

User Name:

Password

Please enter a password for your user account. Note that passwords are case-sensitive.

Password:

Confirm Password:

Email Address

Please enter a valid email address for yourself.

Email Address:

Log-in

User Name

Remember Me?

Password

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.